Creating Safer Healthier Spaces Mixed-Use Neighborhoods

Creating Safer, Healthier Spaces
in Mixed-Use Neighborhoods
Levin Nock Ph.D., Sustainable Building Advisor
2008 Copyleft CC-BY v2.0
www.GreenWayNeighborhoods.net
levin100 AT levinnock.com

Summary: There are well-documented and practical ways to design and build safer, healthier
spaces in mixed-use neighborhoods. For implementation at each of several scales, this report
presents essential design features, benefits, challenges and successful examples, and provides
resources with more information. Benefits to residents include an enhanced sense of safety,
belonging, and neighborliness, as well as improved health and wellbeing.

Scope: This report was prepared and made available pro bono, with the hopes that readers
interested in good design will find the information helpful. It is based in the Pacific Northwest
region of the USA. It might provide a useful starting point for design work in other regions, but
some aspects would need to be re-evaluated. It’s a work in progress, not intended to be complete.
Readers are responsible for using this information with their own judgement, at their own risk. If
you would like to receive or provide more details for any of the topics mentioned, please contact me.

Contents
1 Each Unit Built Green............................................................................................................. 2
1.1 Design Features .............................................................................................................. 2
1.2 Benefits .......................................................................................................................... 3
1.3 Challenges...................................................................................................................... 3
1.4 Examples........................................................................................................................ 4
1.5 Resources ....................................................................................................................... 4
2 Shared, Semi-Private Pocket Parks.......................................................................................... 4
2.1 Design Features .............................................................................................................. 4
2.2 Benefits .......................................................................................................................... 5
2.3 Challenges...................................................................................................................... 5
2.4 Examples........................................................................................................................ 6
2.5 Resources ....................................................................................................................... 6
3 Neighborhood with contiguous greenway network .................................................................. 7
3.1 Design Features .............................................................................................................. 7
3.2 Benefits .......................................................................................................................... 7
3.3 Challenges...................................................................................................................... 8
3.4 Examples........................................................................................................................ 8
3.5 Resources ....................................................................................................................... 9
4 Community: Group of neighborhoods around a central business district .................................. 9
4.1 Design features............................................................................................................... 9
4.2 Challenges.................................................................................................................... 10
4.3 Examples...................................................................................................................... 10
5 Cities with slow traffic separated from fast traffic in 2 separate, dedicated networks.............. 11

Safer, Healthier Spaces Levin Nock p. 1 of 11

1 Each Unit Built Green
1.1 Design Features
1.1.1 Solar Access (temperate climate zones, Northern hemisphere)
• Each unit should have some exterior walls on the north and south sides. Glazing on the
north and south walls of each unit, and possibly north-facing clerestories, provides even
daylighting throughout the day.
• Any glazing on the east and west is carefully considered, such as an east window in the
breakfast nook to catch the morning sun. Any west-facing windows are kept small to
minimize the late-afternoon glare and summer heat gain that large west-facing glazing
would create.
• Overhangs such as eaves, porches, upper-story decks and trellises above south-facing
windows limit the summer heat gain. Also low-e coatings, on windows where overhangs are
not practical.
• A substantial part of the roof faces approximately south. Each unit can have south-facing
domestic hot water panels and PV panels, and north-facing monitors or clerestories for
daylight (possibly with controllable openings for passive solar cooling). With careful design
of the roof, each unit will have its own usable solar exposure, with minimal shading from
neighboring units. The roof should have ridge-lines on an east-west axis, to provide large
south-facing slopes for solar appliances, and north-facing clerestories for even daylight
without heat gain.
• Whether or not the new units are built with PV arrays and solar domestic hot water panels,
they should be designed and built with conduits to carry plumbing and wires from the roof to
the utility area, so that solar utilities can be easily added later.
• Trees planted on the south and southwest sides of buildings should be short enough, at
maturity, not to block the solar access of the roof.
• While daylighting is specific to each unit, solar heat and electricity can be shared. An
alternative to the per-unit requirements above, would be to provide district-level solar power
generated on the roof of a nearby school or commercial building.

1.1.2 Water catchment
When the footings are poured for a new building, it is relatively easy to dig space for a large
catchment tank, for water. This could be as simple as a large impermeable bladder contained under
a porch, or in the corner of a basement. If the space is available, and the roof is made of metal or
other suitable material, then residents can choose whether to add a complete water catchment
system.

1.1.3 Sprinkler fire prevention
Interior water sprinklers can be installed cost-effectively by the plumbers who subcontract the
conventional plumbing. If every unit has a sprinkler system for fire prevention, then some fire
departments are more cooperative about permitting narrow streets. Narrow streets are essential to
maximize the land area that’s available for greenspace and for buildings. Also, with more and more
research by Sightline.org and others documenting the hazards of common fire retardants, the future
contents of residential homes might be more flammable than they are today.


1.1.4 Visitability
• One zero-step entrance, at the front, back or side of the house
• All main floor doors, including bathrooms, with at least 32 inches of clear passage space
• At least a half bath, preferably a full bath, on the main floor.
• Basic requirement for all units, with a few exceptions as needed for difficult sites.

1.1.5 Greenbuilding systems
Earth Advantage Platinum www.earthadvantage.com (Pacific Northwest)

BuiltGreen (various state and local programs)

LEED for Homes pilot https://www.usgbc.org/DisplayPage.aspx?CMSPageID=147

In a Net Zero Energy building, over a year’s time, the building produces as much energy as it
consumes. While this goal is not yet as systematic and commonplace as the Earth Advantage
system, there are significant local examples proving that it’s possible. One of the most systematic
versions of this idea is the “Passive House” movement in Germany. One of the simplest ideas to
borrow from this movement, is that the ratio of exterior surface area to interior volume should be
minimized, typically by building multifamily units rather than single family residences.

Living Building Challenge, Cascadia Greenbuilding Council. www.livingbuilding.org

1.2 Benefits
Lower and more predictable utility bills, for as long as the house stands.
Greater comfort and safety during utility outages.
Residents are healthier, from breathing cleaner air indoors.
Marketing opportunities
Guarantee to pay the difference if the monthly heating bill exceeds a limit within the period
of the home warranty.
Portland-area RMLS will list green features of new homes, starting in 2007.

1.3 Challenges
1.3.1 Solar
Some mortgage programs such as FHA require that a home be aligned with the street. Thus, unless
the streets are straight lines on north-south or east-west axes, it may be difficult to design a south-
facing roof. In Village Homes (VH), all houses have a south-facing roof, the streets have gentle
curves, and the houses were financed using non-FHA mortgage sources. Most VH houses have a
private, fenced patio facing the street; the house might not be lined up parallel with the patio fence.

The good news in Oregon is that solar appliances with grid-tied PV still work pretty well, on an
annual basis, as long as the roof does not face north. While due-south is best, a street can follow a
gentle curve, with houses facing the street, and all houses can still have a roof that faces roughly
south.


1.4 Examples
In Village Homes, all units have a south-facing roof. CC&R’s (Covenants, Conditions and
Restrictions) define the “solar rights” of each unit, so that an adjacent unit cannot block a neighbor’s
solar access.

Canada is working on new building code that could eventually make it illegal to build anything less
than a Net Zero building.

German “Passive house” program http://en.wikipedia.org/wiki/Passive_house

Solar domestic hot water and PV in Oregon: http://www.oregonseia.org/

1.4.1 Local Portland, Oregon Net Zero Energy examples include
Blueberry Lane spec homes in NE Portland by developer Billy Reed, website has extensive design
details: http://www.villagegreenhomes.org/

Nathan Good designed Net Zero Cannon Beach home: 2268 sf, 3 bd/2.5 bath, Rich Elstrom
Construction. www.nathangoodarchitect.com/publications/article_pdfs/fhb_feb06.pdf

Tom Kelly’s house in Parkdale, OR designed by Liz Olberding, built by Neil Kelly construction.
http://www.earthadvantage.com/news/item/?key=20

Green Hammer recently built 2 residences.
http://www.theleapfroghouse.com

The Rose house, designed by SERA Architects and built by Coho Construction is a local example of
an Accessory Dwelling Unit.
http://www.oregon.gov/ENERGY/CONS/RES/tax/docs/RoseHouse.pdf

Construction options for the walls of Net Zero homes include insulated rammed earth, Structural
Insulated Panels (SIP), advanced framing (Larson trusses or staggered 2x4’s on 8” or 10” sill plates)
with sprayed-in insulation, insulated concrete forms (ICF), strawbale, and conventional 2x6 walls
with an exterior layer of sealed, taped foamboard sheathing. The basic goal is to make thick walls
with high R-values and no air leaks. While cob and light-straw methods can also accomplish this
goal, they are too labor-intensive for most professional contractors to accomplish profitably.
However, Joshua Klyber is exploring ways that modern German methods of earthen construction can
be adapted to the Pacific NW cost-effectively.

1.5 Resources
Visitability: www.concretechange.org

2 Shared, Semi-Private Pocket Parks
2.1 Design Features
1) Clear sense of semi-private shared space
Bounded by surrounding units.
Clearly delineated entry points from the public street or sidewalk. In an urban setting, entry
points might be tall, locked gates to which all residents have a key. In a suburban setting,


while the entry points might not be locked, a visitor still has a clear sense of entering private
property.
2) Human scale dimensions
height to width ~1:6
Example: St Francis Park h/w ratio is 1:6, 150 ft x 150 ft, flanked by trees & 3-story
apartments of roughly 25 ft height
3) All or almost all units have a view into the common space that the units surround.
Children can play safely, without dedicated adult supervision.
Neighbors notice activity and take ownership to keep the area safe.
4) High quality layout and landscaping
Trees (especially trees close to the perimeter buildings) attract people, promote
neighborhood social ties, reduce crime, and help people feel safer.
For children: play equipment, paths for wheeled vehicles, areas for exploratory play, etc.
For adults: movable chairs & tables to fit the activities of each new day.
5) Each unit has private outdoor space clearly distinguished from the shared space, such as:
Fenced balcony or patio between unit and park
Small private garden between unit and park
Porch or fenced private patio on the streetside
6) Clear boundaries and easy access between what is private (dwelling unit, patio, small private
yard) and what is shared.

(adapted from Clare Cooper Marcus, Professor Emerita in Architecture and in Landscape
Architecture, UC Berkeley)

2.2 Benefits
These features help people feel safe and at home in their neighborhood. This is a smaller scale than
the public life of streets and typical public parks. The presence of these features means that children
can play outdoors safely, conveniently and often. This is especially important when 40% of
elementary schools nationally have either eliminated or shortened outdoor recess, and working
parents have a limited amount of time to dedicate completely to supervised play at a distant park.

“In a series of large-scale, highly controlled field studies,… Trees and grass cover were linked with
greater use of residential outdoor spaces by adults and children, healthier patterns of children’s
outdoor activity, more social interaction among adults, healthier patterns of adult–child interaction
and supervision, stronger social ties and greater resource sharing among adult residents, greater
sense of safety and adjustment, lower levels of graffiti and other signs of social disorder, fewer
property crimes, and fewer violent crimes…

“One striking implication of this body of work is that the location of trees matters at a surprisingly
fine-grained scale. Participants in these studies all have ready access to neighborhood green spaces
and live within a few miles of one of the most extensive examples of urban nature in North
America… Further, the participants in each study live within the same neighborhood, with the same
overall level of tree canopy. Yet in study after study, the finding is that having trees directly outside
one’s own building is different than having those same trees just outside neighborhood buildings. To
fully reap the social benefits of trees then, the urban forest may need to be substantially more tightly
integrated into the residential urban fabric than is currently recommended.” (Kuo 2003)

2.3 Challenges
Many housing developments have common greenspace areas that have become neglected,
unmaintained, dangerous eyesores, because they lack one or more of the design features outlined


above. In areas where new residents have incorporated all of these features (such as Montgomery
Park in Boston’s South End), the common areas have been transformed from eyesores into delightful
amenities. If a well-meaning city planner or other stakeholder claims that common greenspace is
difficult to maintain, and cites an example, then this provides an excellent opportunity to explore
which feature(s) are missing from that particular example.

2.4 Examples
2.4.1 City blocks, with a central shared green in the middle.
St. Francis Square in San Francisco
Southside Park cohousing in Sacramento
On Going Commons in Portland
The Meadows in Berkeley
Greenwich Millenium Village in London (central green roof/park over 2-story parking garage)
London’s Victorian garden squares
MacDougal-Sullivan Gardens and Turtle Bay Gardens in New York City
“Vault Field of Dreams Ad” http://video.google.com/videoplay?docid=3696564454881273741

2.4.2 European “woonerf” neighborhoods in northern Europe.
Narrow, one-way street loops around a central green, with only one entrance/exit point. Pedestrians
share the pavement with cars.

For instance, Cherry Hill, 29 unit affordable housing townhouses in Petaluma CA, built 1992. 22-ft
wide one-way access road with speed bumps around a central green. No through traffic. 4 paved
courtyards off the loop. No sidewalks—traffic is limited and slow so that pedestrians and cars share
the streets safely.

2.5 Resources
www.CommunityGreens.org

Clare Cooper Marcus, “Shared Outdoor Space and Community Life”, ‘Places’ 15(2) pp32-41.
http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1813&context=ced/places

Clare Cooper Marcus and Wendy Sarkissian, “Housing as if People Mattered”, 1986.

Anne Kristin Morris (2002) “Planning for Community Greens in City Neighborhoods”, Masters
Paper, Dept of City and Regional Planning, University of North Carolina at Chapel Hill.
www.communitygreens.org/Resources/AnneMorrisThesis.doc

Frances E. Kuo (2003) “THE ROLE OF ARBORICULTURE IN A HEALTHY SOCIAL
ECOLOGY”, Journal of Arboriculture 29(3):148-155, May
http://treelink.org/joa/2003/may/04Kuo.pdf

Oscar Newman (1996) Creating Defensible Space
http://www.huduser.org/publications/pubasst/defensib.html


3 Neighborhood with contiguous greenway network
3.1 Design Features
3.1.1 Contiguous Greenways
1) ~500 residents share one neighborhood with one contiguous network of greenway paths
2) All residents can walk/wheelchair/bike from their home to the village center without
crossing the street, in less than 10 minutes. In most cases, 5 minutes or less (1/4 mile).
3) Eliminate most (preferably all) pathway/street intersections, using cul-de-sacs
4) Pathways in pleasant greenspace, not beside roads
5) Collect the greenspace in useful units, and minimize pavement
6) Most residents can walk downtown in a fairly direct path, with minimal doubling back or
zigzagging.
7) Every unit is accessible by a pathway on one side and by a road on the other side.
a. In some developments, the front door faces the greenspace. Guest parking lots
provide access to the greenspace, and guests approach the front door through the
greenspace
b. In other developments, the front door faces the street, and the backdoor faces the
greenspace.
8) Natural drainage
a. Narrow, curbless roads along ridges that are the highest elevation in the area
b. Permeable concrete for neighborhood streets: regular concrete mix, without sand
c. Stormwater is managed on the surface, in either flowing streams, ponds, or
bioswales. Plan: any water standing for more than 2 days will be a permanent
water feature, with fish to eat mosquitoes. Or it’s a seasonal pond that dries up in
the summer, with native Oregon frogs.
d. Where feasible, follow existing topographic contours, preserving existing
streambeds
e. Pathways follow close to the streambeds/bioswales, with small bridges or culverts as
necessary
f. Most stormwater on the road drains directly down through the permeable pavement.
Any water that drains off the road, flows around the buildings to the network of
bioswales and streams.
g. Water from some rooftops may flow into a cistern, for use by residents. Any
remaining stormwater from rooftops will flow around the buildings and into the
network of bioswales and streams.

3.1.2 Shared heat source
Ground source heat pump
Steam plant with cogenerated waste heat from commercial/industrial district
Solar thermal hot water on a neighborhood scale

3.1.3 Shared commercial space
The neighborhood center can have office space for local businesses and telecommuters.

3.2 Benefits
A contiguous greenway network with surface management of stormwater provides an attractive
amenity, while eliminating the cost of stormdrains.


In Oregon, creating a condominium can save up to 1 year for permits, compared to a subdivision.

If the principal of an elementary school is expected to know the names of all the students, then the
school cannot hold more than 500 students. 500 people is a good number for a group.

In Village Homes, with less than 1000 residents, the residents know, on average, 40 neighbors and
have 3 or 4 close friends in the neighborhood. In a nearby standard subdivision, residents know 17
neighbors on average and have one friend in the neighborhood.

Permeable concrete: concrete is more durable than asphalt, and with the rising cost of petroleum, the
cost is comparable. The light color of concrete reduces the summer urban heat island effect. The
City of Portland is experimenting with permeable concrete on a section of Going street. While
permeable concrete is not quite as durable as regular concrete with sand, it is suitable for residential
streets (probably not for arterials). Stormwater runoff is a major environmental impact of
development, and permeable concrete pavement can help mitigate this impact.

3.3 Challenges
3.3.1 Regulatory changes that would help
Narrow streets
Minimal, flexible setbacks
Mixed-use zoning
Cluster development
No curbs
Pathways in lieu of sidewalks
Stormwater as surface water
Water catchment and greywater reuse permitted

“Smart Code” is an improvement over most existing local codes, but is based on a system of
connected streets with adjacent sidewalks. This code will need to be modified, to support a network
of paths that are not necessarily adjacent to roads.

3.4 Examples
Village Homes, Davis CA
Radburn, NJ

3.4.1 Shared Commercial Space: Village Homes
Village Homes, a subdivision with fewer than 1000 residents surrounded by residential subdivisions,
has a community center with a swimming pool, children’s playground, one restaurant and offices.
There is usually a waiting list for office space, from residents who want to work close to home.
While the commercial district is very small and quiet, with no retail component, it is an important
amenity for the community. The community ownership of this property is discussed in more detail
below, based on an interview with Judy Corbett, one of the founders.

The commercial property in the town center is owned by a for-profit corporation. This corporation
is managed by a committee of the Village Homes Homeowners Assoc (VH HOA). All the profits
from the corporation go to the non-profit VH HOA.


All residents in the neighborhood pay homeowners dues, for instance, for maintenance of the
landscape and the common property (commercial, community center/pool, etc.). A significant
amount of this money is for 3 gardeners who tend the orchards and other agricultural components.
The developers originally hoped that the agriculture and edible landscape might pay for itself
directly as quot;community supported agriculturequot;, but this has not happened.

The Homeowners' dues are much smaller than they would be, if there were no commercial property.
Nobody receives dividends—the residents simply pay lower Homeowners dues than they would
otherwise.
Legal challenges:
1) A non-profit must be careful about doing commercial work.
2) Most homebuyers are not SEC qualified investors, so they need to buy a home without exactly
buying a share of a private, for-profit corporation.
A very smart lawyer spent significant effort to set up the legal structure properly.
If the commercial property generated income in excess of all the neighborhood expenses, then a
different legal structure might be required.

3.5 Resources
www.GreenWayNeighborhoods.net

Designing Sustainable Communities: Learning from Village Homes, by Judy Corbett and Michael
Corbett., 1999.

Human Scale, by Kirkpatrick Sale. 1980, Reprinted 2007.

4 Community: Group of neighborhoods around a central
business district
4.1 Design features
• All residents can walk/wheelchair/bike from their home to the town center in less than 10
minutes. This is measured along each actual travel path, not a theoretical radius from the
center.
• Eliminate as many pathway/street intersections as feasible, and mitigate any remaining
intersections with traffic lights, tunnels or bridges.
• Pathways in pleasant greenspace, not beside roads
• Group enough neighborhoods together, and provide enough through-traffic, to support a
vibrant central business district
• Shared local schools. Elementary, Middle, and High Schools are all available to students
under their own power. For elementary schools, this means a very short walk or bike ride
along very safe pathways. High school students can bike farther to a more centralized
location, but they still need safe pathways.
• Principles for Walkable Communities
• Ahwahnee Principles, Local Government Commission
• 10 Principles for Smart Growth, Urban Land Institute
• Charter of the New Urbanism, Congress for the New Urbanism
• Principles of Smart Growth, Smart Growth Network
• LEED-ND (Neighborhood Development), United States Green Building Council
• Patrick Condon’s Principles for Walkability


4.2 Challenges
If each neighborhood has 500 to 600 residents, then a thriving business district will need at least 4 to
8 of these neighborhoods surrounding it for pedestrian traffic, plus additional customers who bike or
drive or take the bus from more distant neighborhoods. Each small neighborhood should have its
commercial “center” directly adjacent to the business center of the town.

Comparison data on purchasing power, business activity, and workforce density for all census tracts,
residential ZIP codes, and the 100 largest metro areas in the U.S. is available here:
http://www.uwm.edu/Dept/ETI/PurchasingPower/purchasing.htm
Another free resource is www.esribis.com, with profiles of any community based on zip codes.

Suburban retail centers tend to engage in a winner-takes-all size war, where the largest regional
shopping center on the largest road attracts all the customers, leaving smaller retail outlets with
fewer and fewer customers. http://www.walkablestreets.com/box.htm
In order to maintain a viable commercial center in a suburban region, it is important to manage this
dynamic successfully. One goal is to attract the business of local resident constomers. Walkable
distances along pleasant pathways to pedestrian-oriented storefronts can help with this goal.
Another goal is to somehow attract consumers from a greater distance, without necessarily having
the biggest “big box” on the largest road in the region.

Some businesses require a large number of potential customers, even if they have a “local” flavor.
For instance, a single “Curves” franchise (small neighborhood fitness center for women) needs a
population base of ~10,000 people.

4.3 Examples
4.3.1 Future
I have yet to find good examples of clusters of 500-person groups, with each group defined by clear
physical boundaries. Most urban planning involves groups of 2000 or more people with vague, fluid
boundaries, so the social benefits of small groups are lost. Village Homes and Radburn, NJ are
surrounded by more conventional suburban development. In an urban setting, a single building can
easily hold 500 residents. Somewhere, there are probably midrise urban developments where each
residential building has central courtyard space(s) meeting the guidelines from St Francis Square,
each residential building is within easy walking distance of a commercial core with businesses and
schools, and residents love living there. If you know of any examples, please email me a note,
levin100 AT levinnock.com. Thanks.

4.3.2 Issaquah Highlands
Issaquah Highlands in Issaquah, WA will have a population of 10,000 at build-out, which should
support a thriving commercial district at the main entrance to the development. Most of the
residents will drive through the commercial district in their daily commutes, but relatively few
residents live close enough, or have an inviting path, to walk downtown. Each neighborhood has
~2000 residents.

4.3.3 Orenco Station
Orenco Station in Hillsboro, OR has a popular grocery store and a Starbucks to anchor its
commercial district, and a busy arterial to supply plenty of regional traffic.
http://www.tndwest.com/orencostation.html


While the original residential development is not really in walking distance of the Max stop, new
apartments, townhomes and condos are filling in the high-density area immediately around the Max
stop.

4.3.4 Ladera Ranch
Future research. www.laderaranch.com

4.3.5 Victorian green blocks in London
Future research.

5 Cities with slow traffic separated from fast traffic in 2
separate, dedicated networks
City Population (approx)
Midway City, UT, USA 2,000
Houten, Netherlands 40,000
Davis, CA, USA 60,000
Reston, VA, USA 60,000
Almere, Netherlands 150,000
Venice, Italy 275,000 (1M in the summer)
Calgary, Canada 1,000,000 (limited slow traffic network)


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